Whole Wheat Rosemary Feta Focaccia with Red Onion

Steps

1. In a large bowl, stir the lukewarm water, honey and instant yeast until dissolved.
2. Add the whole wheat flour, the bread flour and half of the crumbled rosemary; mix until no dry patches remain. Cover and rest 20 minutes so the whole wheat bran softens.
3. Sprinkle the salt over the dough and add 15 g of the olive oil (about a quarter); squeeze and fold until absorbed. This is about 82% hydration and 1.8% salt, based on the combined whole wheat flour and bread flour.
4. Cover and let rise at about 75°F (24°C) for 1 1/2 hours, doing a set of stretch-and-folds every 30 minutes for the first hour. It is ready when puffy, about doubled in size and jiggly.
5. Pour 20 g of the olive oil (about a third) into a 9x13-inch pan and spread it over the bottom and sides. Turn the dough into the pan and gently stretch it toward the corners; if it springs back, rest 10 minutes and stretch again.
6. Scatter two-thirds of the crumbled feta over the dough and press it in with your fingertips. Cover and proof at about 75°F (24°C) for 45 minutes, until airy and it springs back slowly when poked.
7. While the dough proofs, preheat the oven to 450°F (230°C) with a rack in the middle.
8. Toss the sliced red onion with 10 g of the olive oil. Dimple the dough deeply with oiled fingers, then top with the onion, the remaining third of the feta, the remaining half of the rosemary and the black pepper.
9. Bake 22 to 26 minutes, until deep golden and the center reads 200–210°F (93–99°C).
10. Brush the hot top with the remaining 10 g of olive oil for a glossy crust. Let cool in the pan 5 minutes, then move to a rack and cool at least 20 minutes before cutting into 12 slices.